After Koretski's retirement from football, he was appointed as a team delegate of Hapoel Ramat Hasharon, and later began serving as assistant coach.

At the end of the season, Koretski was appointed as head coach of Hapoel Ra'anana and led the team to a promotion to Ligat Ha'Al.

Before the 2014–15 season, Koretski was appointed as head coach for Beitar Jerusalem, and was fired on 27 January 2015.

One week later, Koretski was appointed as head coach for Hapoel Petah Tikva, and at the end of the season they were relegated to Liga Leumit.

In January 2016, while Hapoel Petah Tikva were ranked first in Liga Leumit, Koretski decided to move to coach Maccabi Netanya, while Netanya entered a process of liquidation and were ranked 16th in Ligat Ha'Al.